Three scenarios: A skull-rattling gridiron hit leaves a player writhing on the field. A soccer player goes head-first into a goalpost and is carried, unconscious, off the pitch. A guy bangs his head real good on the garage door and sees stars, then comes to after a minute and feels “fine.” Who should go to the hospital?

All of them!

Odds are they won’t, though: A new survey by global healthcare company Abbott revealed that a full 64% of U.S. adults didn’t seek treatment the last time they hit their heads “very hard.”

Is “very hard” enough to cause a concussion? Absolutely. According to the CDC, “Any bump, blow, or jolt to the head…that disrupts the normal function can cause a concussion.” Not all impacts will result in a concussion, of course, but if there’s a brief change in mental status or consciousness, or an extended period of unconsciousness or memory loss after the injury, then, bingo! That’s a concussion.

Now, if you’re an athlete, there’s some potentially good news: Currently being tested on the sidelines at sporting events is a noninvasive device designed to, in just 12 minutes, determine if an athlete has had a concussion by using two earbuds—a transmitter and a receiver—to pulse a series of sound waves through his cranial cavity. If the noninvasive gizmo, developed by the Vanderbilt Sports Concussion Center, is effective, it could be approved by the FDA by 2017.

But the rest of us will still have only ourselves to trust to make the right decision and get the care we need. So the next time you smash your head hard enough that the room spins, err on the side of caution and see a doc.